Posts Tagged "Peru"

Climate Change Increases Flood Risk in Peru

Posted by on Dec 28, 2016 in All Posts, Featured Posts, Images, News, Policy and Economics, Science | 0 comments

Climate Change Increases Flood Risk in Peru

Spread the News:ShareThe rising danger of glacial lake flooding in a warmer climate has important implications for humans and animal populations in Peru’s Cordillera Blanca. A recent study in CATENA by Adam Emmer et al. examined a large swath of nearly 900 high altitude Peruvian lakes in the mountainous Cordillera Blanca region, studying their susceptibility to outburst floods in light of modern climate change. An outburst flood occurs when the dam containing glacial meltwater, usually comprised of either glacial ice or a terminal moraine (glacial debris lying at the edge of the glacier), fails. Glaciologist Mauri Pelto commented in the American Geophysical newsletter that the moraine dams are “just comprised of gravel, sand and clay dumped by the glacier” and “high water levels caused by upstream floods, avalanches or landslides can cause failure,” leading to major damage of the landscape. The team’s research elucidated that the incidence of glacial lake outburst flooding (GLOF) is increasing and the general distribution of alpine lakes is shifting upward in the region as temperatures warm.  Knowing a lake’s size, configuration and type allows local water management in the Cordillera Blanca to be improved, according to Emmer et al. By mapping lakes with the classification of either moraine-dammed or bedrock-dammed, the team’s analysis can help local hydrological experts improve water management techniques for the changing distribution of alpine water. It also contributes to the scientific community’s overall understanding of ongoing environmental change. By studying the Cordillera Blanca region’s alpine lakes through a combination of remote sensing (high resolution aerial imagery and measurements) and field observations, Emmer’s team categorized 882 lakes by their size and altitude, ultimately referencing their findings with historical data to observe water redistribution over the last 60 years. Emmer et al. established that glacial lakes had expanded in size and number at higher elevations and disappeared at lower elevations since the 1951 study by Juan Concha in the same region. This finding confirms that environmental change and glacier retreat are strongly correlated in the high alpine. Results from the analyses showed that from 1948 to 2013, lakes that remained in already deglaciated areas tended to be resilient and generally maintained water levels throughout the 65-year examination. Moraine-dammed lakes in particular resisted disappearing despite glacial retreat, suggesting that bodies of water dammed by materials other than ice were more adaptable to recently warmer temperatures.  The team also noticed that despite the recent resiliency of moraine dammed lakes, glacial lake outburst flooding was caused predominantly by these dams in the early portion of the Cordillera Blanca’s glacial retreat, in the 1940s and 1950s. Flooding in more recent years has occurred in bedrock-dammed lakes. Although glacial lakes were recorded to have shifted from 4250-4600m in the late 1940s to predominantly above 4600m today, no statistically significant trend was established relating outburst flooding to any particular elevation. In order to reduce the risk of flood damage in local communities, Emmer et al. suggested continuous monitoring of young, developing proglacial lakes, using extensive flood modeling and outburst susceptibility assessments to account for future changes in the glacier. Understanding that the melting of glaciers is accelerating in a warming world, the need for more intensive local efforts in response to the threat of flooding is apparent.   The Peruvian government has responded to high lake levels in the mountains of the Cordillera Blanca by “building tunnels and concrete pipes through the [weakest] moraines to allow lake drainage to safe levels,” according to Pelto. The government then rebuilds the moraines over the drainage system to strengthen it. By incorporating the monitoring techniques suggested by Adam Emmer, the government has the...

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Roundup: Tragedy in Antarctica, Antimony and Glacier Risks

Posted by on Oct 31, 2016 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Tragedy in Antarctica, Antimony and Glacier Risks

Spread the News:ShareRoundup: Tragedy, Antimony and Risk   Prominent Climate Scientist Dies in Antarctica New York Times: “Gordon Hamilton, a prominent climate scientist who studied glaciers and their impact on sea levels in a warming climate, died in Antarctica when the snowmobile he was riding plunged into a 100-foot-deep crevasse. He was an associate research professor in the glaciology group at the Climate Change Institute at the University of Maine. He was camping with his research team on what is known as the Shear Zone, where two ice shelves meet in an expanse three miles wide and 125 miles long. Parts of the Shear Zone can be up to 650 feet thick and ‘intensely crevassed.’ Dr. Hamilton’s research, aided by a pair of robots equipped with ground-penetrating radar instruments, focused on the impact of a warming climate on sea levels. He was working with an operations team to identify crevasses.” Learn more about the tragedy here.   Antimony Found in the Tibetan Glacial Snow Journal of Asian Earth Sciences: “Antimony (Sb) is a ubiquitous element in the environment that is potentially toxic at very low concentrations. In this study, surface snow/ice and snowpit samples were collected from four glaciers in the southeastern Tibetan Plateau in June 2015… The average Sb concentration in the study area was comparable to that recorded in a Mt. Everest ice core and higher than that in Arctic and Antarctic snow/ice but much lower than that in Tien Shan and Alps ice cores… Backward trajectories revealed that the air mass arriving at the southeastern Tibetan Plateau mostly originated from the Bay of Bengal and the South Asia in June. Thus, pollutants from the South Asia could play an important role in Sb deposition in the studied region. The released Sb from glacier meltwater in the Tibetan Plateau and surrounding areas might pose a risk to the livelihoods and well-being of those in downstream regions.” Read more about the research here.   Managing Glacier Related Risks Disaster in Peru The Climate Change Adaption Strategies: A recently edited book, “The Climate Change Adaptation Strategies – An Upstream – Downstream Perspective,” edited by Nadine Salzmann et al., has several chapters on glaciers. The chapter “Managing Glacier Related Risks Disaster in the Chucchún Catchment, Cordillera Blanca, Peru” discusses some of these glacier related risks: “Glacial lakes hazards have been a constant factor in the population of the Cordillera Blanca due their potential to generate glacial lake outburst floods (GLOF) caused by climate change. In response, the Glaciares Project has been carried out to implement three strategies to reduce risks in the Chucchún catchment through: (1) Knowledge generation, (2) building technical and institutional capacities, and (3) the institutionalization of risk management. As a result, both the authorities and the population have improved their resilience to respond to the occurrence of GLOF.” Explore more related chapters here. Spread the...

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New Study Offers Window into Glacial Lake Outburst Floods

Posted by on Aug 11, 2016 in All Posts, Featured Posts, Science | 0 comments

New Study Offers Window into Glacial Lake Outburst Floods

Spread the News:ShareA recent geological study has shed some light on the cause of a major, yet elusive destructive natural hazard triggered by failed natural dams holding back glacial lakes. The findings show how previously unrecognized factors like thinning glacier ice and moisture levels in the ground surrounding a lake can determine the size and frequency of Glacier Lake Outburst Floods, or GLOFs. The risks of these glacial floods are generally considered increasingly acute across the world, as warming atmospheric temperatures prompt ice and snow on mountain ranges to retreat and to swell glacial lakes. Landslides in moraines as triggers of glacial lake outburst floods: example from Palcacocha Lake (Cordillera Blanca, Peru), published in  Landslides in July 2016, centers its study on Lake Palcacocha in the Cordillera Blanca mountain region of central Peru.  Since Palcacocha is one of almost 600 lakes in the Cordillera Blanca mountain range dammed by glacial moraines, the population of the region lives under serious threat of GLOFs. The Landslides article is a step in understanding a previously understudied geological phenomenon.  As little as five years ago scientists acknowledged the lack of research on the subject. “We don’t really have the scientific evidence of these slopes breaking off and moraine stability… but personal observations are suggesting there are a lot of those…” said Ph.D. environmental historian Mark Carey in a 2011 video where he describes GOLFs.   Glacial Lake Outburst Flood risks do not always emanate from mountain glacier meltwater that flows downstream. As this study shows,  in some instances, trillions of gallons of water can be trapped by a moraine, a formation of mixed rock, which forms a natural dam.  A weakening over time, or a sudden event, such as a landslide, could then result in the moraine dam’s collapse. The massive amount of water is suddenly then released, and a wall of debris-filled liquid speeds down the mountainside with a destructive force capable of leveling entire city blocks. GLOFs have presented an ongoing risk to people and their homes dating back to 1703, especially in the Cordillera Blanca region, according to United States Geological Survey records.  In December of 1941, a breach in the glacial moraine restraining Palcacocha Lake led to the destruction of a significant portion of the city of Huaraz and killed approximately 5,000 people. Scientists and government agencies, like the Control Commission of Cordillera Blanca Lakes created by the Peruvian government following the 1941 GLOF, have recognized the need to better understand and control GLOFs.  The study found that as global temperatures rise and glaciers retreat, greater amounts of glacier melt water will continue to fill up mountain lakes, chucks of ice will fall off glaciers, and  wetter moraines will become  more prone to landslides. The team of mostly Czech geologists and hydrologists (J. Klimeš; J. Novotný; I. Novotná; V. Vilímek; A. Emmer; M. Kusák; F. Hartvich) along with Spanish, Peruvian and Swiss scientists (B. Jordán de Urries; A. Cochachin Rapre; H. Frey and T. Strozzi) investigated the ability of a glacial moraine’s slope to stay intact, called shear strength, and modeled the potential of landslides and falling ice to cause GLOFs. After extensive field investigations, calculations and research into historical events, the study found several causal factors that can determine the severity of a GLOF.  These include size and angle of entry of a landslide,  shape and depth of the glacial lake, glacier thickness and human preventative engineering such as canals and supporting dams.  Frequency and size of a landslide is determined by the stability of surface material, a characteristic called shear strength, which can be influenced by something as subtle as the crystalline shape of the predominant mineral in the rock. The scientists determined that waves caused...

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First global analysis of the societal impacts of glacier floods

Posted by on Jul 28, 2016 in All Posts, Communities, Featured Posts, Interviews, Science | 0 comments

First global analysis of the societal impacts of glacier floods

Spread the News:ShareTwo British researchers recently published the first global inventory and damage assessment of the societal consequences incurred by glacial lake outburst floods (GLOFs). They revealed that glacial lake outburst floods (GLOFs) have been declining in frequency since the mid-1990s, with the majority released by ice dam failures. Glacial hazard specialists Jonathan Carrivick and Fiona Tweed spent 18 months scouring the records of over 1,348 GLOFs, determining that such floods have definitely claimed over 12,400 lives since the medieval period. Their work stems from a need to strengthen data on glacier lakes. “There was very very little quantitative data out there on the importance of glacier lakes, from a societal point of view,” Carrivick said in an interview with GlacierHub. He explained that this recent paper was a natural progression from his earlier research, which focused on modelling hydrological, geological and geomorphological processes. Based purely on frequency, Carrivick and Tweed found that north-west North America (mainly Alaska), the European Alps (mainly Switzerland), and Iceland are the “most susceptible regions” to GLOFs. However, the impacts of these events have have often been minimal, as they occur in sparsely populated, remote regions, and in places where resilience is high. The greatest damage has been inflicted upon Nepal and Switzerland — respectively accounting for 22 percent and 17 percent of the global total damage reported. When Carrivick applied the normalized ‘Damage Index,’ which considered GDPs of the affected country (used as a crude proxy for ability to mitigate, manage and recover), he found that Iceland, Bhutan and Nepal have suffered the “greatest national-level economic consequences of glacier flood impacts.” Historically, Asian and South American GLOFs have been the deadliest, taking the lives of 6,300 and 5,745 individuals since 1560 respectively. However, these figures are dominated by only two catastrophes, which accounted for 88 percent of the 12,445 fatalities confirmed by Carrivick and Tweed. The first, in December 1941, saw over 5,000 Peruvians perish in Huaraz, when a landslide cascaded into the glacial Lake Palcacocha. The second event, swept away more than 6,000 Indians from across Uttarakhand in June 2013, as torrential rains triggered outburst floods and landslides. The study’s authors adopted a method for normalizing damage assessments new to GLOF hazard analysis, striving to fairly compare the cataclysmic impacts of outburst flooding on communities around the world. They found that there has actually been a decline in number of floods since the 1990s, which was surprising to the researchers, given that a 2013 study which they had conducted found that the number and size of glacial lakes has increased, as the world’s ice masses have wasted. Carrivick stated that he was “very interested in the fact that, apparently, so few glaciers have lakes that have burst [0.7% of the total], on a global scale.” He added, “it beggars belief that there isn’t a higher percentage of those lakes that have burst at some point.” In their paper, the pair suggest that the “apparent decline” could be attributed to improved successful stabilisation efforts, natural resilience, greater awareness and preparedness in threatened communities, or declined number of GLOFs from ice-dammed lakes. An additional factor may be that some glacial floods are missing from the English-language record. Carrivick revealed, “We have a contact in China who says that there’s a lot of unpublished floods…that individual has not been able to send us the data yet.” Government restrictions on the flow of potentially sensitive information has contributed to this partial release of data. Carrivick also noted that new data is continually being published, in many cases in foreign languages. He referenced a recent issue of the Geological Journal, which...

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Preparing Peruvian Communities for Glacier-based Adaptation

Posted by on Jun 27, 2016 in Adaptation, All Posts, Communities, Featured Posts, Policy and Economics | 0 comments

Preparing Peruvian Communities for Glacier-based Adaptation

Spread the News:ShareAs climate change quickens the pace at which Andean glaciers are melting, Peruvian communities located downstream from glaciers are becoming increasingly vulnerable to natural disasters. The Peruvian national and subnational governments, the Swiss Development Cooperation, the University of Zurich, and the international humanitarian group CARE Peru have executed a collaborative multidisciplinary project to help two affected communities respond to glacier retreat and the increased risk of disaster. The first phase of the project ran from November 2011 through 2015. The project’s second phase, which is expected to run from 2015 to 2018, continues its work of risk reduction and climate change adaptation, while expanding its scope to hydropower production research. Peru is home to one of world’s largest concentrations of tropical glaciers, most of which are located in the Cordillera Blanca in the Ancash region, along a section of the Andes in north central Peru. The Cordillera Blanca contains more than 500 square kilometers of glacier cover, accounting for roughly 25 percent of the world’s tropical glaciers. High mountain ecosystems such as the Cordillera Blanca are no stranger to major geophysical events, such as ice and rock avalanches, debris flows, and glacial lake outburst floods (GLOFs). Glacier lake outburst floods are considered to have the most far-reaching impacts of any other glacial hazard. In the last few decades, Peru has already experienced several major natural disasters due to glacier melt and subsequent flooding. In 1970, a major earthquake in Ancash activated a glacial lake outburst flood and subsequent debris flow that destroyed the town of Yungay, killing around 20,000 people. More recently, in April of 2010, glacial lake Laguna 513 in the Ancash region triggered a flood outburst that created significant property damage in the downstream town of Carhuaz, which is home to roughly five thousand people. In order to mitigate the risk of future natural disasters, this collaborative project worked from 2011 to 2015 to enhance the adaptation capacities of two communities located downstream of glaciers: Santa Teresa, in Cuzco, and Carhuaz, in Ancash. The project aimed to better prepare and equip these two communities to deal with the threat of glacial lake outburst floods by creating specialized integrated risk reduction strategies. In Santa Teresa, a micro-watershed area of the Sacsara River, the project installed an comprehensive monitoring system, which provides the town with early flood warnings via radio communication tools, provided localized risk analysis, and supported the creation of community and municipal development plans, as well as the integration of emergency plans into 17 local schools. In Carhuaz, project collaborators helped the municipality establish a water resources management committee in order to increase the capacity of local and interagency decision-makers to collaborate in managing risk. The project also installed an early-warning system for glacier outburst floods, as well as planned evacuation routes and disaster responses. The project implemented curriculum plans containing climate change adaptation and risk management into 30 schools in Ancash. The project’s various scientific and technical experts also conducted flood scenario models, which they shared with local decision-makers to help identify areas of potential risk. To date, the project has trained more than 90 public officials, agency staff, and university professors on climate change, adaptation, and risk management measures. CARE Peru estimates that the project has directly benefited over six thousand people in these Carhuaz and Santa Teresa, and has indirectly benefited many more. The project particularly emphasized gender and power dynamics that contribute to vulnerability. The project trained local leaders on gender equality issues and women’s empowerment and encouraged balanced gender participation in the adaptation planning for both communities.  University of Zurich glaciologist and project contributor Christian Huggel...

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